SHOOTOUT: Seven 6G Solid State Drives

In case you haven't noticed, the prices on SSDs have dropped significantly. Plus there are some new 6Gbps SSDs that have come into the market to challenge the supremacy of the SandForce based SSDs. We gathered some of the "usual suspects" to see how they compared in various stress tests.

To squeeze out the maximum performance, we connected them to a fast 6Gbps host adapter, the HighPoint RocketRAID 2722 which we installed in a 2010 Mac Pro. Here's what we saw:

Intech's QuickBench - The Standard test includes measuring random transfer speed of small blocks from 4K to 1024K. We averaged five cycles. (Highest number means the fastest in megabytes per second.)

Finder Duplicate measures not only how fast the SSD can read from and write to itself, but the 1GB test image is incompressible data that some SSDs handle much faster than others. (Highest number means the fastest in megabytes per second.)

DigLloyd's DiskTester has a random I/O operations test that reveals how many transactions a storage volume can perform in a second. Below is the "burst" rate at which data can be written to each test SSD. (Highest number means the fastest in operations per second.)

WHAT WE LEARNED
The "odd balls" in this test were the Corsair Neutron GTX and OCZ Vertex 4. They are the only two 6Gbps SSDs in the test that don't use the SandForce SF-2281 controller. The Neutron GTX uses the LAMD LM87800 controller. The Vertex 4 uses the Indilinx Everest 2. For more details on these two SSDs (and others), consult our RELATED LINKS below.

As you can see, they were significantly faster in some tests compared to the SandForce based SSDs and significantly slower in other tests. For example, both SSDs were faster than the SandForce SSDs in the Finder Duplicate test. However, in the QuickBench small random read test, both were slower than the others. Needless to say, all of them are faster than HDDs and 3Gbps SSDs.

Sometimes consumers are confused by the different models of SSD offered by the same company. Or they hear terms like asynchronous and synchronous. The asynchronous SSDs are the lower priced "consumer" models while the synchronous SSDs are touted as "enterprise" models. Notice the SwiftData asynchronous SSD's performance in the Finder Duplicate test. (Other examples of asynchronous SSDs include the OWC Electra and OCZ Agility.) We prefer synchronous SSDs since they perform best in all situations.

Reliability? All of the SSDs were rated at 2 million hours of mean time between failure rate or MTBF so that's not so helpful. We have experienced no failures on the current test batch but have had failures with some 3Gbps SSDs in the past with only light use. We won't name names because our experience is considered "anecdotal." In every case, the manufacturer replaced the SSD. Since our focus is on performance rather than reliability, suffice to say that you should have a backup strategy for all your SSDs and HDDs. Anything that can go wrong will go wrong.

STEALTH SSD
Rather than buying a 6Gb/s Host Adapter for your Mac Pro that may or may not boot OS X or may or may not require special drivers, many Mac Pro users are discovering products like the Accelsior, which has Dual LSI SandForce SF-228X processors with High-Performance Tier 1 Synchronous-NAND mounted on an x4 PCIE card. Some of you many have noticed the Accelsior in the graphs that was "undocumented" in the GRAPH LEGEND. Sneaky. You can see the dual processors provide faster performance compared to the "normal" 6G SSDs. Though our sample had 240GB, you can get capacities up to 1 Terabyte.

If you already have a 6Gbps SSD you want to use as a boot drive, you can also install it on a PCIe card like Apricorn Velocity Solo x2. It can be expanded to a second SSD but the installation will be tricky. For dual SSDs on a PCIe card, we like the design of the Sonnet Technologies Tempo SSD Pro. We plan to test it and report on it in a future article.

RELATED LINKS
Anandtech does a thorough job of explaining the technical details on the various SSDs: